I hear great things about the ohlins. Are they worth the thousand dollar investment? I see some less expensive alternatives on ebay coming out of Australia. I have an 03, so no adjustment.

Lack of adjustment has zero to do with the crappiness of the OEM units.
The dampers are just as bad in early no adjuster and later adjuster forms.
At the least the early ones came with a spring rate, unlike the later ones that came with a mush rate better suited for a pixie on a bike weighting 200 # less.

I don't completely hate the oem shock.. It takes corners okay considering my 200 lb frame. My big problem is with the way it takes bumps and dips in the road.. Can I have the oem shock rebuilt with a spring that fits my weight better?

I don't completely hate the oem shock.. It takes corners okay considering my 200 lb frame. My big problem is with the way it takes bumps and dips in the road.. Can I have the oem shock rebuilt with a spring that fits my weight better?

for that kind of money/work, you'd be better off ditching the OEM shock and picking up a progressives unit. however they are not available anymore so you only choices really are the penske or ohlins. You're better off ditching the OEM shock no matter what you do. In other words, rebuilding the OEM shock is not a viable goal since it is simply just complete trash due to the valving, internals, and what not.

If you want a great breakdown on the OEM unit and why its not worth rebuilding it, contact LDH as he's VERY knowledgeable on the topic and will tell how things are.

another good source is mcromo. he's tracked his bike enough that he became the test pig for Penske to build a rear shock unit specifically for the 919.

This is a very good question.
One thing I have always wondered about and simply do not know, is what the low speed compression damping force curve is like for the Ohlins.
I've wondered if it is noticeably different and better than the Penkse.
I've never been able to find the Ohlins curve to do a compare.
Both are good units.
Low speed compression is an issue on the 919 because of the unlinked swing arm.
919s are squat meisters.
This is really only an issue under hard riding, in particular track days.
For the typical 919 rider, you simply can not go wrong with the Ohlins, and there is more support for it than there is the Penske.
I say that as a pro Penkse guy. (pro as compared to con, not professional)